The SMOKE light illuminates amber when:

The SMOKE light illuminates amber when smoke is detected specifically in the avionics ventilation system. This alert is crucial as it indicates a potential hazard in the cockpit or avionics area, which can threaten aircraft safety. The detection of smoke prompts crew members to take necessary actions, such as initiating smoke removal procedures, checking for electrical fire sources, or preparing for possible emergency situations.

In contrast, other scenarios listed would trigger different warnings or alerts. For instance, the presence of a fire in GEN 1 would activate fire detection systems associated with the engine or APU rather than the general smoke indication. Similarly, a short circuit in GEN 1 would not trigger the amber SMOKE light but might result in electrical system alerts. Testing the emergency generator is a controlled condition and would not indicate any smoke presence. Understanding these specific indications is vital for ensuring the appropriate response to different in-flight threats.